The invention discloses a high sensitive biochemical sensor based on a resonance oscillation type micro cantilever beam structure. The biochemical sensor comprises a resonance oscillation chamber, a cantilever beam and a Whist bridge type detection circuit, wherein a micro column structure (3), a liquid storage tank (4) and a liquid leakage hole (5) through which biochemical solution flows are etched at the free end of the cantilever beam; the support end of the cantilever beam is connected with the Whist bridge type detection circuit; the Whist bridge type detection circuit is composed four U-shaped piezoresistance bars (1), three input electrodes (8, 9, 10) and two output electrodes (7, 11); and the four piezoresistance bars (1) are connected with the input electrodes (8, 9, 10) and the output electrodes (7, 11) through a signal transmission line (2). With the adoption of the biochemical sensor, micro biochemical molecules can be sensed with a high sensitivity by detecting the frequency change after an object to be tested is absorbed; biochemical molecules with micromass can be detected; and the biochemical sensor can be widely used in engineering fields such as medicine and chemistry.